デジタル油圧の建設機械向けパイロット元圧回路への応用に関する研究

Abstract

Pilot-pressure supply circuit of construction machinery consumes 2-3% of engine's horsepower. A method of improving energy efficiency is studied by many researchers. Switched Inertance Hydraulic Converters (SIHC) which is one type of digital hydraulic circuit has been proposed as a solution to reduce throttling loss through control valve in a hydraulic circuit. A digital-hydraulic pressure reducing circuit is an example of SIHC which may show high energy efficiency because it does not use a throttling orifice. It can obtain output flowrate larger than supply flowrate. This paper aims to apply the digital-hydraulic pressure reducing circuit to pilot-pressure supply circuit of construction machinery. A control method of the pilot pressure to follow demanded pilot pressure is proposed. A simulation model is experimentally verified. The proposed control method is validated. Controllability and loss reduction effect are investigated by simulation based on transient pressure and flowrate data of an actual construction machinery in operation.